tp5(thinkPHP5框架)captcha验证码配置及验证操作示例

composer require topthink/think-captcha 1.* -vvv

'captcha' => [    // 验证码字符集合3.
  'codeSet' => '2345678abcdefhijkmnpqrstuvwxyzABCDEFGHJKLMNPQRTUVWXY',     // 验证码字体大小(px)5.
  'fontSize' => 28,     // 是否画混淆曲线7.
  'useCurve' => false,     // 验证码图片高度9.
  'imageH'  => 50,    // 验证码图片宽度11.
  'imageW'  => 200,     // 验证码位数13.
  'length'  => 4,     // 验证成功后是否重置    15.
  'reset'  => true
  ],

<div class="yzm">
  <img src="{:captcha_src()}" class="verify" onclick="resVerify()" alt="验证码" />
<a href="javascript:resVerify();" rel="external nofollow"  >看不清，换一张</a>
</div>

<img src="{:captcha_src()}" class="verify" 
onclick="javascript:this.src='{:captcha_src()}?rand='+Math.random()" >

$captcha=input("captcha");
 //验证
if (!captcha_check($captcha)){
  exit(json_encode(array('status'=>0,'msg'=>'验证码错误')));
}

//验证码验证码
$captcha = new Captcha();
if (!$captcha->check(input("captcha"))){
  return $this->error("验证码错误");
}